XP Home does not come as a x64 version.
How to determine whether a computer is running a 32-bit version or 64-bit version of the Windows operating system.http://support.microsoft.com/kb/827218
Windows XP If you have Windows XP, there are two methods to determine whether you are running a 32-bit or a 64-bit version. If one does not work, try the other.
- Click Start, and then click Run.
- Type sysdm.cpl, and then click OK.
- Click the Generaltab. The operating system is displayed as follows:
- For a 64-bit version operating system: Windows XP Professional x64 Edition Version < Year> appears under System.
- For a 32-bit version operating system: Windows XP Professional Version <Year> appears under System.
Note <Year> is a placeholder for a year.
- Click Start, and then click Run.
- Type winmsd.exe, and then click OK.
- When System Summary is selected in the navigation pane, locate
Processor under Itemin the details pane. Note the value.
- If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of Windows.
- If the value that corresponds to Processor starts with ia64 or AMD64, the computer is running a 64-bit version of Windows.
If you cannot determine the operating system bit count with these methods, go to the "Next Steps" section (of the KB article)